1. Field of the Invention
This invention relates to pressure transducers and more particularly to capacitive type pressure transducers.
2. Description of the Prior Art
There exist in the prior art several types of capacitive pressure transducers. These pressure transducers have at least one common difficulty. This difficulty is a result of the effect upon the capacity of the capacitive pressure transducer of the negative temperature coefficient of the modulus of elasticity of the material of the diaphragms from which the capacitive transducer is made. To compensate for this effect, several techniques have been developed. Such techniques include such things as electronic compensation via the use of sensitive components such as thermistors and capacitors. Such techniques while substantially compensating for this effect add to the complexity of the capacitive pressure transducer. In addition, these techniques require individual testing of the capacitive pressure transducers and matching of the measured characteristics of the capacitive pressure transducer to those of the compensation components or the matching of the compensation components to the characteristics of the capacitive pressure transducer. In either case, the cost of manufacture of such a capacitive pressure transducer is increased. Accordingly, it is a general object of the present invention to provide a capacitive pressure transducer with increased temperature stability.
It is another object of the present invention to provide a capacitive pressure transducer with increased temperature stability which is relatively simple and low in cost.